CrunchSlaughtered
RPM Ruler
I had some doubts that you hate me and now can be sure. It's nothing less than a torture to make me write this technical info in my far from perfect English, but I'll try.
Porsche uses a Hybrid Permanent Magnet Synchronous Motor. it's called hybrid because it uses a magnetic field from a permanent magnet in the rotor and a magnetic field from electro-magnets in the stator and is working according to the Law of Lorenz (not sure how is correctly written in English), which explained with simple words says that when two magnetic fields are fighting is occuring perpendicular force-the one that rotates the rotor. The magnetic field rotates (controlled from the frequency converter)from the coils of the stator due to the altering current and needs a lot of copper wiring. In order for the PMSM to be more efficient the permanent magnet (rotor) should be very strong and this is achieved with it's bigger size and rare earths (Neodym)-so heavy, bulky and expensive.
The motor used by Tesla Model 3 (and Model S from recently) is called Permanent Magnet Switchable Reluctance Motor. But the Permanent magnet in the name is totally deceiving. It can work without such magnets but Tesla uses very small amount of them in the coils of the stator in order only to boost the electromagnets. In this motor the magnetic field is not rotating but pairs of two counter laying coils are switched on then off while the next pair is switched on and so on. The magnetic field runs from one of the switched coils through the rotor to the other switched coil, according to the Reluctance Law in which the magnetic field flows to the easiest path. So there is only one magnetic field and due to this substantial reduction of heat generation. The rotor is made of simple ferous material, is light and extremely heat resistant. It almost cannot be overheated, and this is very important, because while the stator is outside it can be easily cooled by air or water, but the rotor is closed inside and can not be cooled properly.
So the RM is much lighter, is way more efficient especially in half load situations which are the most common with EVs, has much faster reaction, more responsive, less copper in the stator, can work at higher rpms, has almost 0 rare earths, more reliable and almost indestructible, it's also more compact. It's superior in almost every category. It's a new technology and before Tesla it was available in only small power outputs (because the coils work like condensers and the bigger the power, the slower they discharge - can not be switched off fast, which is very essential). somehow Tesla has managed to overcome this problem and to create a motor with much higher power output.
To make the long story short the RM is at least 10 years ahead of the PMSM.
